The present invention relates to a polyaniline/carbon black composite and a preparation method thereof, especially to a polyaniline/carbon black composite and a preparation method thereof that are applied to dielectric material with microwave absorption or conductive coatings with corrosion resistance.
The research and development of conductive coatings have been over a half-century. Working as conductive layer, electromagnetic wave shielding layer and antistatic coating, the conductive coatings have broad perspective and increasing market demands. The membrane surface of the conductive coating has higher resistance, charge generated thereon is not dissipated effectively so that static charges tend to accumulate thereon. This leads to certain limitations on applications of some respects such as dust proofing and bacteria resistance in medicine, protection from electric shock in medical operations, static protection for preventing static ignition and explosion in mine environment and petrochemistry, dust-proofing for protection of integrated circuit, and fiber accumulation in spinning industry. The conductive coating is special coating or meeting various requirements. The conductive coating is coating with conductor and semiconductor properties and the conductivity is above 10−10 S/cm, being applied to various fields such as electronic and electric appliance industry, printed circuit board, switches, marine antifouling coatings, electrothermal material, and electromagnetic wave shielding, and surface protection.
While using carbon series as filler in preparation of conductive coating, carbon black (mainly high conductive furnace carbon black and acetylene carbon black), graphite and carbon fiber are mixed together. In literatures, graphite as conductive filler is added with epoxy resin and it is found that the conductivity is dramatically improved when amount of the graphite is over 50 wt. %. However, addition of graphite results in poor physical and mechanical properties and poor processability. This leads to limits on usefulness of the conductive coating.
The conductive, corrosion resistant and microwave absorbing polyaniline has features of light weight, good plasticity, easy raw materials acquisition, easy synthesis and high stability. Thus polyaniline together with high conductive, corrosion resistant and microwave absorbing nano-scale carbon black form a polyaniline/carbon black composite material. The polyaniline/carbon black distributed in substrate (epoxy resin, organic silicone) can overcome defects of poor physical property, poor mechanical property and poor processability caused by large amount of graphite being added. Moreover, the present invention has features of high conductivity, corrosion protection and high microwave absorption without adding large amount of carbon black. Thus weight of conventional conductive coating is reduced so as to facilitate the applications of material in conductive elements, corrosion protection or microwave absorbing elements.